Light



JAMES A. AIED, or MONTREAL, aunnnc. cannu a LIGHT.

Specification of Letters Patent.-

Application filed December 6, 1919. Serial No. 342,934.

lamp supports, and the object of the invention is to provide adjustable means to support a lamp which will permit of the lamp being moved to a position over any part of a table or the like in a single horizontal plane.

A further object is to provide an apparatus of this kind in which the lamp may be adjusted vertically into any one of a number of horizontal planes and adjusted laterally in any one of the horizontal planes.

There are of course a large number of adjustable lamp supports, but very few.

of these are adapted for use over a large table and those which are intended for use over a large table have the disadvantage that as the lamp is adjusted laterally, it is also raised.

According to the present invention, a lamp such as an electric. lamp connected to a flexible cord is supported from the ceiling of a room by means of a continuous cord, passing from fixtures on the ceiling located approximately over the corners of the table to be illuminated to a lamp holder. This cord also passes between the ce ling fixtures and, if vertical as well as lateral adjustment of the lamp is desired, a loop is provided in the cord where it passes between the ceiling fixtures and a counterbalance weight suspended in the loop.

In the drawings which illustrate the 1nvention;

Figure 1 is a perspective view illustrating.

the device installed over a table.

Fig. 2 is a plan view of one of the ceiling fixtures.

Fig; 3 is a sectional view on the line 33, Fig. 2. j

Fig. 4 is an elevation of the lamp holder.

Fig. 5 is a section on the line 5-5, Fig. 4.

Referring more particularly to the drawings, 11 designates the ceiling of a room and 12 a table or other surface which it is desired to illuminate. Four cord holding fix- This invention relates to improvements in tures 13, 13*, 13 and 13 are secured: to the ceiling at points over the corners of the :table 12, and preferably outside of the corners, so as to define a rectangle larger-than the table top and concentric withthe table top. A continuous cord 14- is passed through these fixtures and through a lampholder 15 in a manner more fully explained hereafter, so that a length. ofthe cord extends between the holder 15 and each of the fixtures 13', as clearly shown in Fig. 1. Each .of the fixtures 13 preferably comprises a disk 16 of suitable thickness having a cir-v cumferential groove 17 in, its edge and a central aperture 18 open from the lower surface. A channel 19 is provided connecting the central opening 18 and the bottom of the groove. The disk is secured to the ceiling by a screw or the like 20-, the head of which is accessiblethrough the recess 18 but is located above the end of the passage Patented Dec. 2'7, 1921..

19, as clearly seen in' Fig. 3. The upper surface of the disk may be cut away in its central portion, so that only a rim'21 remains, which will engage the ceiling. This surface formation of-thedisk increases the 1 friction between the disk and ceiling. by

localizing the loadimposed when the screwis tightened, and also decreases the possibility of thefixture being insecurely mounted by reason of unevenness of the ceiling.

The lamp holder 15 comprises a body 22 which for convenience may be conical in its.

upper part and-cylindrical in its lower part. The lower part of the body is hollowed out to provide a recess 23 for the upper part of an ordinary electric lamp socket 24, and is provided with a threaded nipple 25 tofwhich the socket is screwed. A passage 26,'is provided leading from, the upper end of the nipple 25 through the conicalgsurface of the holder. If desired, an'insulating bushing 27 may be screwed into the outer end of this passage to guard a fiexible conductor .28

leading to the lam socket against abrasion.

Near its lower en the body 22 is provided with a circumferential groove 29, from which a pair of passages 80 and 30 located at diametrically opposite points in the holder lead upward to the top thereof, where,

leaves the fixture 13 and extends to the fixture 18, running into the circumferential groove thereof through the passage 19 and recess 18, and extends down to the holder, entering the passage 30. From the passage 30 ,the= cord passes in the unoccupied half of the groove 29' to the passage 30, up through the passage 30to the central recess of the fixture 13. The cord passes through this fixture in the same manner as described for th previous ones and extends from the groove of this fixture to the groove of the fixture13, passes through the fixture, emerging from the central recess 18, and back to the starting point X. It will thus be seen that those portions of'the cord between the lamp holder and ceiling fixtures leave or enter the centers of the fixtures, while those portions of the cord extending between fixtures pass from groove to groove of the fixtures. The tension of the cord and also the frictional resistance to sliding in the fixtures may be adjusted by loosening the screws 20 and rotating the disks 16, so as "to cause a greater or lesser amount of the grooves to be occupied by the cord, and then tightening the screws.

When it is desired to move the lamp from the central position shown in full lines, Fig.

1, to any other position over the table, ity

is grasped in the hand and moved to the desired position. During this movement, the cord slips through the grooves and passages of the holder and ceiling fixtures. If the movement is parallel to one edge of the table, the cord slippage is entirely in the holder, while if the lamp is moved in a direction a right angles to the first movement, the cord slippage is entirely in the ceiling fixtures. If the movement is a compound of the two, 2'. 6., diagonally of the table, there will be combined slippage of the cord in the holder and in the ceiling fixtures. If they ceiling fixtures are located properly with respect to the size of the table and the height of the ceiling, there'will be no appreciable alteration in the elevation of the lamp, that is to say, the lamp will move substantially in a single horizontal plane. In reality, the cord runs in two loops through the holder and any construction giving this effect with sufficient friction will be satisfactory. In other words, the circumferential groove is not essential of itself but is merely a means of holding the cord in loops.

While an endless cord as described is preferable, the same result may be obtained by fixing the two ends of the cord either at the tures may location of adjacent ceiling fixtures or to the holder. In the first case, the cord will run in two loops through the holder but, in the second case, it will run in only one loop. With the ends of the cord fixed, the device ofiers more resistance to adjustment and there is much greater relative movement between the cord and holder.

In order that the lamp may be adjusted vertically, the portions of cord passing between the ceiling fixtures are led through any suitable supports 31 located on the ceiling, so that two loops 32 of cord depend in which a counterbalance weight 33" is suspended preferably by means of pulleys 34. It is found that a single counterbalance weight gives the best results as if two are used, onebetween each pair of ceiling fixtures, all the slack in the cord will eventually be taken up at one weight or the other, owing to unequal friction in the ceiling fixtures.

It will be seen that without the counterbalance, the movement of the lamp is really in an ellipsoidally curved path, but that if the long diameters of this path (determined by the distance between ceiling fixtures) is sufiiciently greater than the short diameters (determined by the distance between lamp and ceiling), the curvature will be very slight so that the departure of the lamp from a horizontal plane will not be appreciable. The counterbalance willpermit elongation of the effective length of cord, so that the lamp may be moved absolutely in a horizontal plane if desired.

"When the lamp is adjusted to the desired position, it will remain as set, owing to the friction of the cords in the ceiling fixtures and holder, which is sufficient to overcome any tendency to movement. The counterbalance weight is substantially inactive as long as the lamp is moved in a single hori- Zontal plane and, when the lamp israised or lowered, the counterbalance weight serves to keep the cord in tension and in proper frictional contact with the fixtures.

Obviously six, eight or more ceiling fixhe usedin connection with a holder having three, four or more passages 30, the number of holder passages being half the number of fixtures. 7

It will be understood that various modifications may be made in the design of the ceiling fixtures 13 and. 31 and the lamp holder 15 without departing from the spirit. of the invention, which, therefore, must'not be construed as limited to the specific details of construction shown, and the illustration must be regarded as descriptive and not as limitative.

Having thus described my invention, what I claim is 1. A lamp support comprising a plurality therein, and a single continuous cord passing through the channels of the fixtures and holder in sliding frictional contact therewith and suspending the holder in such manner that the lamp may be moved in any desired direction in a horizontal plane without appreciable elevation.

2. A device according to claim 1, in which the ceiling fixtures are" arranged in pairs and the cord passes between the fixtures of each pair and hangs in loops between the fixture pairs, the holder being located in said loops in slipping engagement therewith.

3. A lamp support, comprising a plurality of ceiling fixtures and supports having cord channels therein, a single continuous cord assing freely through the channels of the fixtures and supports and hanging in loops therebetween, a lamp holder located in alternate loops and a counterbalance located in the remaining loops in slipping engagement therewith.

4. A lamp support including a plurality of fixtures each of which comprises a circumferentially grooved disk having a central recess and a passage connecting the groove and recess, a lamp holder and a cord passing from the fixtures to the holder through said central recess and between the fixtures from groove to groove.

5. A lamp support comprising a plurality of ceiling fixtures having cord channels therein, a lamp holder and a cord passing through the channels of the fixtures and of the holder and suspending the. holder, said fixtures being adjustable to regulate the tension of the cord and the length of fixture surface in contact with the cord.

6. A lamp support comprising a plurality of ceiling fixtures having cord channels therein, a lamp holder comprising a body having a circumferential groove and a pair of passages leading from the groove ant meeting at a point in the axis of the body,

and a cord passing from the fixtures to the holder through the passages and groove of the holder. I

7 A lamp support comprising a plurality of overhead fixtures, each circumferentially grooved and centrally recessed and provided with a channel connecting the groove and central recess, a lamp holder having a circumferential groove, and passages leading from said groove and meeting in the axis of the holder above the groove, and a continuouscord passing from the central recess of each fixture through the passages and groove of the holder, said cord also passing from fixture to fixture.

8. A device according to claim 7, including supports in combination with the .fixtures and in which the cord hangs in loops between the fixtures and supports, alternate loops passing through the holder, and a counterbalance weight hangin in the remaining loops. I

9. In a device of the class described, a lamp holder having cord passages therethrough adapted to frictionally engage a cord, a series of overhead'fixtures adapted to frictionally engage a cord, and a continuous cord passing through the holder and fix tures, said cord passin through each fixture once and through tie holder, a number of times equal to half the number of fixtures.

10. A device of the class described,'comprising a series of four overhead cord fixtures arranged at the corners of a "rectangle, a lamp holder having a pair of cord passages therethrough, and a continuous cord passing through said fixtures and holder,

those portions of the cord passing between fixtures at two opposite sides of the rectangle passing also through the holder and those portions of the cord passing at the remaining two sides of the rectangle being disconnected from the cord holder.

In witness whereof, I have hereunto set my hand. 7

. JAMES A. AIRD. 

